Device for forming filaments



0. OHLSON.

DEVICE FOR FORMING FILAMENTSf APPLICATION FILED MAY19. 1919,

1 33732 Patented Apr. 20, 1920.

OLOF OHLSON, OF WEST NEWTON, MASSACHUSETTS.

DEVICE FOR FORMING FILAMENTS.

Specification of Letters Patent.

Patented Apr. 2%, 1920.

Application filed May 19, 1919. Serial No. 298,315.

To all whom it may concern:

Be it known that I, OLOF OHLsoN, a citizen of the United States, andresident of West Newton, in the countyof Middlesex and State ofMassachusetts, have invented an Improvement in Devices for FormingFilaments, of whichthe following description, in Connection withthe'accompanying drawings,- is a specification, like referencecharacters on the drawingsrepresenting like parts.

This invention relates to a device for forming filaments for theproduction of thread or yarn made from cellulose compounds or similarmaterial.

In the manufacture of such threads or yarns, the cellulose compound isin liquid form, in solution, and the liquid is forced through a numberof minute orifices into a coagulating bath which causes the material tosolidify as its issues in the form of a jet from each orifice and thusproduces a filament, which is associated with a number of similarfilaments which are slightly twistedtogether and upon emergence from thecoagulating bath constitute a strand of the yarn which may subsequentlybe utilized in the manufacture of thread or fabric.

The device which is used in this process and which contains a number oforifices corresponding to the number of filaments that are to beassociated to form a single strand of the yarn or thread is commonlycalled a spinneret, and the present invention consists in a novelconstruction of the spinneret.

The production of a satisfactory spinneret is attended with considerabledifiiculty as it must be strong enough to withstand considerablepressure, and the orifices by which the filaments are formed areextremely minute, but for a satisfactory product require to be of equalsize in the same spinneret, and heretofore the spinnerets have commonlybeen made of glass and are thus fragile and liable to breakage.

In accordance with the present invention the main body of the spinneretis of metal, being in the form of a cup, the walls of which are thickenough to withstand the pressure to which the spinneret is subjected inthe operation of forcing the solution through the same.

It has been found impracticable to form the minute orifices in the metalbody of the spinneret by drilling or punching, but I have discoveredthat suitable orifices can be formed in small relatively thin plates ordisks by punching, orwith some materials by drilling, and in accordancewith the present invention the main bod of the spinneret is providedwith a nuin er of relatively large perforations or holes correspondingin number to the number of filaments desired, and in each of saidperforations is secured a relatively thin disk having the minuteperforation which constitutes the jet orifice by which the filament ismade.

Figure l is a side elevation of a spinneret embodying this invention;

Fig. 2, an end elevation thereof, and

Fig. 3, a sectional detail on line X Fig. 2 on a greatly enlarged scaleto show the construction at one of the orifices.

The main body 2 of the spinneret may be of usual form and is composed ofmetal which may be drawn to the proper shape, which is that of a cupprovided with a flange 3 around its open end, and having its closed endor bottom 4 (see Fig. 2) provided with the desired number of orifices tocorresppnd to the numberof filaments to enter into a single strand ofthe yarn which is the product of the apparatus to which the spinneretpertains.

In the example illustrated, there are 16 such orifices and they areextremely minute, being scarcely visible to the naked eye in the actualstructure.

The wall or body of the spinneret 2 has to be of considerable thicknessin order to withstand the pressure under which the liquid is forcedthrough the orifices and it has been found impracticable to providesuitable orifices by perforations formed directly in the wall of thespinneret when made of metal, and in accordance with the presentinvention the bottom portion 4 of the spinneret in which the orificesare to be contained is provided with relatively large perforations oropenings 5, shown in Fig. 3 as counterbored to form a shoulder 6 betweenthe inner and outer surfaces of the end wall of the spinneret.

In each of the openings 5 there is secured an orifice plate 7 which'asshown in Fig. 3 is pressed tightly into the counter bore and against theshoulder 6.

The orifice plate '2 is relatively thin as compared with the wall of thespinneret in which it is secured and it is preferably recessed as shownat 8 on one side to reduce the thickness at the middle, where it isprovided with a minute perforation 9 that constitutes the orificethrough which the solution is forced to form the filament.

It is to be understood that as shown in Fig. 3, the dimensions aregreatly exaggerated as the passage or orifice 9 is too small to becapable of correct representation of its actual size by drawing.

The orifice plates themselves are so small that although the fluidpressure is large, the area of the orifice plate exposed to pressure isso small that the total pressure upon it is only very slight and isinsufficient to distort or dislodge the orifice plate. lVith a pressureof two hundred pounds to the inch, the pressure on each orifice plate isless than a pound.

It is an advantage that the part in which the orifice is formed is verythin, as it makes the length of the bore quite short as compared withthe usual construction, and the orifice is less likely to become cloggedin use and is more readily cleared or freed if it should at any timebecome clogged.

The orifice plates being of uniform construction are capable of beingmanufactured economically and with the required degree of accuracy anduniformity and it is possible in some cases to replace one or moreorifice plates in a spinneret if it becomes permanently clogged ordamaged in any way without requiring a complete new spinneret as is thecase when the orifices are formed in the body of the spinneret itself,with which construction a single defective orifice necessitates thediscarding of the en tire spinneret, if a satisfactory product-is to beobtained.

What I claim is:

1. A spinneret or device for forming filaments from a liquid solutioncomposed of a cup like metallic body having a plurality of relativelylarge passages through the bottom wall ofthe cup combined withrelatively thin orifice plates secured in said passages each providedwith a minute perforation or orifice, substantially as described.

2. A spinneret or device for forming filaments from a liquid solutioncomposed of a cup like metallic body having a plurality of relativelylarge passages through the bottom wall of the cup combined withrelatively thin orifice plates secured in said passages each being ofreduced thickness at its middle part and provided with a minuteperforation through said reduced portion.

3. In a spinneret or device for forming filaments from liquid solution,a cup like metallic body portion having a plurality of relatively largepassages through the bottom wall of the cup, each counterbored toprovide a shoulder between the inner and outer surfaces of said bottomwall, combined with relatively thin orifice plates contained in saidpassages and seated against said shoulders, each orifice plate beingprovided with a minute perforation, substan tially as and for thepurpose described.

In testimony whereof, I have signed my name to this specification.

OLOF oHLsoN.

